Valve lash settings

You need to check piston to valve clearence before trying it .030 is about the limit
 
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You can do it with the head on with a degree wheel and dumby spring
 
I wouldn't play with fire without talking to zach about this, now if your building a motor or doing the dummy spring like Jeremy is talking about then fine.

Jim
 
DISTURBED said:
You need to check piston to valve clearence before trying it .030 is about the limit
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Sorry im still in vacation mode .030 is piston to head clearance
DISTURBED said:
You can do it with the head on with a degree wheel and dumby spring
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check it at 10* BTDC and 10*ATDC that will be your closest the valves come to the pistons. I check both valves at both degrees because i can never remember which is checked before and which is after and use a dial indicator on top of the retainer
 
Gives me an excuse to get valve reliefs and a bigger cam if I break it right LOL...
^^ good info I have heard 15* also, any idea where I can get a dummy spring for these engines?
 
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Lostnwalmart said:
Gives me an excuse to get valve reliefs and a bigger cam if I break it right LOL...
^^ good info I have heard 15* also, any idea where I can get a dummy spring for these engines?
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Hardware store is likely to have a spring which will work just fine.
 
NickTF said:
A story that forever stuck with me was when speaking with one of the higher ups at Crane Cams. A drag racer was having problems loosing a ton of e.t. Come to find out the issue at hand was the particular rpm he was doing his burnout in was causing harmonices in the valve springs superheating them and turning them into jello going down the race track. A simple increase in burnout rpm to get the valve springs out of that harmonic took care of the problem. Good luck finding that one out on paper when figuring out if a spring will go into coil bind with your desired cam lol.
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Wow, that's unreal right there. Makes you wonder how long he actually fought with that before finding that conclusion.
... best part about it (unlike most problems) is it was a free fix!
 
Lostnwalmart said:
Gives me an excuse to get valve reliefs and a bigger cam if I break it right LOL...
^^ good info I have heard 15* also, any idea where I can get a dummy spring for these engines?
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Regarding fly cut pistons. If they are not needed for the cam you are installing, I would not get them. Some people say that they reduce the swirl and in turn the combustion efficiency and burn rate. The argument states that the peaks and valleys on the top of the piston grab the air and slow the swirl down. We are working with this on our new cylinder head project. Another lost benefit is the fact that you will lose spoolup and efficiency due to lower compression. On large cams you lose spoolup due to the large intake profile and the fact that on the compression stroke you push a lot of air back into the intake because the intake is open while the piston is coming up. Get some of that spool back with better swirl and higher compression.

That is why we designed our cams the way we do. We try our best to design all but our largest cams so that they will drop in. We have quite a few customers running some large cams without flycuts.

This is just an opinion, but a certain amount of swirl is needed in a performance engine. Don't throw it away if you don't have to.
 
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Very valid points zach. This truck has had the cam in it since about January last year and runs great but I should have gone with a 188/220 but was afraid of degreeing it in at the time. In your opinion would I be able to run .010 lash on the exhaust?
 
Hamilton Cams said:
This is just an opinion, but a certain amount of swirl is needed in a performance engine. Don't throw it away if you don't have to.
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This is absolutely true (at least at lower speeds). This is one reason 4 valve engines suffer in low end power compared to an otherwise equivalent 2 valve engine. Too much flow, equal on both sides of the chamber (at least when considering flow co-planar to the deck surface).

And yes, I realize the irony of my user name and this being my first post.
 
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